Tissues Flashcards
Epithelial tissue
- Covers surfaces
- Cells connected
- Separates compartments
- Cells define function
- Diversity of secondary functions
- Forms glands
Connective Tissue
- Connects!
- Extracellular matrix + fluid defines structure and function
- Liquid to solid matrix
eg- blood, bone adipose
Muscle tissue
- Contractile
- Long thin cells
- Cytoplasm of cells packed with contractile apparatus
- Shorten lengths, close down spaces
- Skeletal, smooth, cardiac muscle
Striated
highly ordered arrangement of contractile proteins.
cardiac muscle
Is kind of a hybrid of both smooth and skeletal muscle.
contains:
- striations
- nucleus is more round and in the middle
- interclated disc
skeletal muscle
contains:
- striations
- nucleus is on top (periphery)
smooth muscle
doesn’t have striations
has nucleus in the middle
Non-Striated
less ordered arrangement of contractile proteins
Nervous tissue
- Communication
- Neurons + support cells
- Receives, generates and transmits electrical signals
- Integrates information
eg - spinal cord, cerebellum
Neurone: Basic component of nervous tissue
Neuronal function
- similar in all animals
Plasma membrane electrical signals
- generation (nerve impulses/action potentials)
- conduction to farthest points of cell.
Neurons - 4 regions
- cell body (soma),
- dendrites,
- axon,
- terminals.
Epithelial tissue
Covers surfaces
Separates compartments
epithelium and endothelium
How does epithelial tissue maintain coverage of surfaces?
No contact inhibition
Cell - cell junctions
Cell - ECM junctions
Cell – cell junctions
- Desmosomes
- Tight junctions
- Gap junctions
Desmosomes (adhering junctions; macula adherens)
looks like “]|[”
Function = firm anchorage
in absorptive endothelium
Tight junctions (occluding junctions)
looks like “X”
Function = seals intercellular spaces
in intestine endothelium
Gap junctions (communicating junctions; nexus)
looks like “X” or “O” with many “daisies” inside
Function = cell to cell communication
in cardiac muscle - interclated discs
Desmosomes, Tight junctions
Maintain integrity of epithelial layer (surface covering)
Basement membrane contains
BL = Basal Lamina RL = Reticular Lamina
Epithelium – secondary roles
Thick – wear and tear
Thin - diffusion
Epithelium – secondary roles
Movement - Cilia
Cilium:
- Finger like projection from apical surface (in trachea)
- Tubulin doublet